To be able to unload a dump body of an underground truck, for instance, the dump body is provided with a controlled tailgate adapted to be moved between a closed and an opened position. The dump body can either be pivotably or fixed arranged at the underground truck. When the dump body is fixed arranged at the underground truck a so called ejector gate is placed at the front end of the dump body and adapted to eject the cargo from the dump body when the controlled tailgate is in its opened position.
Particularly, at a type of underground truck, a so called teletram, which is provided with a fixed dump body and which is used for unloading cargo in areas with low ceiling height, in which area a pivotable dump body can not be used, the controlled tailgate moves downward towards the rear wheel unit, when the tailgate opens for unloading ore.
When the controlled tailgate of a teletram of the above-mentioned type is opened a problem arise in that the available distance of motion for opening the controlled tailgate is limited, i.e. the height from the ground to the bottom of the dump body is limited. This results in that the cargo/ore that can be loaded on the dump body is limited to height of controlled tailgate. The side walls of the dump body are usually higher than the height of controlled tailgate in its closed position. Therefore, the rear portion of the side walls of the dump body usually inclines obliquely backward towards the upper edge of the controlled tailgate, whereby a dead space is formed where no cargo can be loaded.
A way of reducing this problem at known teletrams is to the design the controlled tailgate in the form of a circular arc, and to let a portion of the lower part of the arc-shaped, controlled tailgate to move in a circular movement in between the rear wheel unit of the teletram. In this way it is possible to increase the height of the controlled tailgate and thereby the loading capacity of the dump body. However, the height of the tailgate remains lower than the height of the side walls of the dump body.
It has now turned out that it would be desirable to increase the loading capacity of the dump body, preferably by increasing the height of the tailgate, whereby the side walls of the dump body may have the same height over its entire length.